unstarted car 3 years

Tackle all the basics-pull the plugs and clean it

First thing, pull your air-cleaner cover and check for rodent presents past the air filter. If their are, don't start it cause you'll kill it. If there aren't, then change the oil, change all the filters, drain the old gas, and dump a bottle of Gas line anti-freeze into the tank when you put more in(gas line anti-freeze is basically alcohol and will help de-gum the lines and such) Make sure that you have a friend who is good with cars look it over before you start it to make sure that you covered all your bases, then fire it up!

Chance are good you will have problems. Some will be immediate and some will be on going as you drive it. Expect brake work, potential brake lines or fuel lines. Anything that is rubber, such as hoses, belts, vacuum lines present questions from dry rot. Anything that is moveable may be seized of very stiff.
I would be inclined to expect this to be a problem child from the similiar long setting cars I have seen.

Before attempting cranking it, shoot some oil or penetrating fluid into the cylinders and turn the engine over by hand to make sure the cylinders move okay.